The present invention relates to an apparatus for developing light-sensitive materials; particularly to the technology for providing a compact developing apparatus in which the developing solution in a small sized developing tank is substantially hermetically sealed from outside air, in order to prevent oxidization and evaporation of the developing solution.
Processing apparatuses of a conventional type have had processing tanks in the form of an open top bucket and it has been impossible to overcome the problem of processing solution leaking through small cracks or gaps on the side or the bottom of the processing tank. In these types of processing tanks it has been impossible to tightly close the opening in the upper portion of the processing tank where light-sensitive materials pass through. Therefore, a floating cover was placed on the surface of the processing tank, or a certain type of gas which is inert with the processing solution was filled in the upper portion of the processing tank, or a certain type of floating materials which is endurable against the processing solution, was floated thereon for the purpose of reducing the area of the surface of the processing solution. However, the oxidization by air or the evaporation of the processing solution still could not be prevented. So, the level of processing characteristics for light-sensitive materials is very difficult to be kept stable. Especially, in the photo-finishing laboratory (shop) where color photographic processing is small in quantity, the control of the processing solution stability seems to be almost impossible to conduct.
The method to decrease the area where processing solution in the processing tank contact the air is only effective for the decrease of the ratio of the deterioration by oxidization or evaporation of the developer. The above method cannot prevent the deterioration or evaporation of the developer effectively or completely. Especially in case where the operation ratio of the light-sensitive material processing apparatus is extremely low, it is supremely important to prevent the deterioration or evaporation of the propcessing solution from the view point of maintaining the level of color photographic developing quality stable or decreasing the operation cost of the processing apparatus.
Moreover, in case of the conventional open top processing tank, the processing solution warps upward at the contact point between the wall of the tank and the processing solution. So, as the area of the liquid contacting air in this portion is increased and therefore the oxidization begins to contaminate the processing tank, the oxidized solid portion falls into processing solution. This becomes one of the causes of trouble in processing. Therefore, various methods have been studied to solve this problem. If a photosensitive material can be fed directly into the processing solution under the condition that the processing tank is hermetically kept and fully filled with the processing solution and expelling the air inside the processing tank completely, contact between air and the processing solution in the tank cannot happen, resulting in effective prevention of deterioration by oxidization or evaporation. In the above-mentioned method, however, the important technical theme is how to feed the photosensitive material directly into the processing solution without leakage of the processing solution from the processing tank having therein an inlet for a light-sensitive material. The present invention was devised from the above-mentioned viewpoint. The object of the present invention is to provide a light-sensitive material processing apparatus and method in which deterioration by oxidization and evaporation of the processing solution in the processing tank are prevented and a light-sensitive material can be fed directly into the processing solution without leakage.